Presently, the electrification of automobiles is being strongly promoted, in particular lithium-ion batteries being the focus of research. In order to be of interest for the consumer, batteries must guarantee a long service life (>10 years) when used in electric cars. This means that the cell voltage and the energy freed during discharging should still be at approximately ≧90% of the output values even after 10 years. In particular so-called high-energy materials such as the high-energy NCM (LiMO2:Li2MnO3 where M=Nickel (Ni), cobalt (Co), manganese (Mn)) so far do not yet fulfill these requirements. Although so far the HE-NCM supplies high start voltages, in the course of its service life it shows a significant loss of voltage (voltage fade) along with a drop in capacity (capacity fade). For this reason, HE-NCM, which is generally of high interest, is so far not suitable for commercial use.
It is understood that it is generally conceivable to dope redox-inactive elements such as Mg(II) and Sn(IV), which show no change in the oxidation stage and no migration inside the material during cyclization and thus stabilize the structure of the material in order to reduce the voltage fade. Dopings of HE-NCM with Mg and Sn are known from the literature. Although introducing redox-inactive elements reduces the drop in voltage and capacity over time, this is tied to an undesirable loss in start capacity and start voltage of the cell.